Prof. Örs Legeza is the head of the Strongly Correlated Systems “Lendület” research group as well as a scientific advisor at the Wigner Research Centre for Physics of the Hungarian Academy of Sciences in Budapest. He received his PhD from the Budapest University of Technology and Economics in 1997 and joined the Institute for Solid State Physics and Optics of the Hungarian Academy of Sciences afterwards (which has since merged into the Wigner Research Centre for Physics). At the same time, he spent time at various European institutions such as FAU at Erlangen-Nuremberg, ETH Zurich or LMU Munich (as an Alexander von Humboldt awardee). He is currently also a visiting professor at Philipps University Marburg, Germany.
Selected Awards
2021, Academy Prize of the Hungarian Academy of Sciences
2018, Humboldt Research Award of the Alexander von Humboldt Foundation
2012, Lendület Award of the Hungarian Academy of Sciences
2009, Bolyai Plaquette Award of the Hungarian Academy of Sciences
2005, Gombás Pál Award of the Hungarian Physical Society
2003, Young Researcher Award of the Hungarian Academy of Sciences
2000, Bolyai János Award and Research Scholarship of the Hungarian Academy of Sciences
Research Interests
Örs Legeza’s main research interests focus on the development of novel tensor network state (TNS) methods and their application to strongly correlated quantum many-body systems to simulate and study magnetic properties in solid states, exotic quantum phases, complex molecular clusters, ultracold atomic systems or nuclear structures. For the method development he combines established methods for simple networks (MPS, MERA, tensor trees) with concepts from quantum information theory and computational mathematics to push the current frontier of moderate system size to much larger and more complex systems.
Selected Publications
V. Ivády, G. Barcza, G. Thiering, S. Li, H Hamdi, J-P. Vhou, Ö. Legeza, A Gali, Ab initio theory of negatively charged boron vacancy qubit in hBN, npj Computational Materials volume 6, Article number:41 (2020)
I. Shapir, A. Hamo, S. Pecker, C.P. Moca, Ö. Legeza, G. Zarand, S. Ilani, Imaging the Wigner Crystal of Electrons in One Dimension , Science Vol. 364, Issue 6443, pp. 870-875 (2019)
F.M. Faulstich, A. Laestadius, Ö. Legeza, R. Schneider, S. Kvaal, Analysis of The Coupled-Cluster Method Tailored by Tensor-Network States in Quantum Chemistry , SIAM J. Numer. Anal. 57, 2579 (2019)
K. Gunst, F. Verstraete, S. Wouters, Ö. Legeza, D. Van Neck, T3NS: three-legged tree tensor network states , J. Chem. Theory Comput., J. Chem. Theory Comput. 14, 4, 2026–2033, (2018)
C. Krumnow, L. Veis, Ö. Legeza , J. Eisert, Fermionic orbital optimisation in tensor network states, Phys. Rev. Lett. 117, 210402 (2016)
L. Veis, A. Antalik, F. Neese, Ö. Legeza, J. Pittner, Coupled cluster method with single and double excitations tailored by matrix product state wave functions, Journal of Physical Chemistry Letters, 7 (20) 4072-4078 (2016)
Ö. Legeza, L. Veis, A. Poves, J. Dukelsky, Advanced density matrix renormalization group method for nuclear structure calculations PHYSICAL REVIEW C RAPID COM 92:(5) 051303. 5 p. (2015)
Sz. Szalay, M. Pfeffer, V. Murg, G. Barcza, F. Verstraete, R. Schneider, Ö. Legeza, Tensor product methods and entanglement optimization for ab initio quantum chemistry, INTERNATIONAL JOURNAL OF QUANTUM CHEMISTRY 115:(19) pp. 1342-1391. (2015)
S. Knecht, Ö. Legeza, M. Reiher, Communication: Four-component density matrix renormalization group, JOURNAL OF CHEMICAL PHYSICS 140:(4) 041101. 5 p. (2014)
Ö. Legeza and J. Sólyom, Two-site entropy and quantum phase transitions in low-dimensional models, PHYSICAL REVIEW LETTERS 96:(11) 116401. 4 p. (2006)
Ö. Legeza and J. Sólyom, Optimizing the density-matrix renormalization group method using quantum information entropy, PHYSICAL REVIEW B CONDENSED MATTER (1978-1997) 68:(19) 195116. 9 p. (2003)
Barcza, Gergely; Werner, Miklós Antal; Zaránd, Gergely; Pershin, Anton; Benedek, Zsolt; Legeza, Örs; Szilvási, Tibor: Toward Large-Scale Restricted Active Space Calculations Inspired by the Schmidt Decomposition. The Journal of Physical Chemistry A 126 (51), 2022, 9709-9718 mehr…BibTeX
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Friesecke, Gero; Barcza, Gergely; Legeza, Örs: Predicting the FCI energy of large systems to chemical accuracy from restricted active space density matrix renormalization group calculations. , 2022 mehr…BibTeX
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Friesecke, Gero; Graswald, Benedikt R.; Legeza, Örs: Exact matrix product state representation and convergence of a fully correlated electronic wavefunction in the infinite-basis limit. Physical Review B 105 (16), 2022 mehr…BibTeX
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Gebhard, Florian; Bauerbach, Kevin; Legeza, Örs: Accurate localization of Kosterlitz-Thouless-type quantum phase transitions for one-dimensional spinless fermions. Physical Review B 106 (20), 2022 mehr…BibTeX
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Moca, Cătălin Paşcu; Werner, Miklós Antal; Legeza, Örs; Prosen, Tomaž; Kormos, Márton; Zaránd, Gergely: Simulating Lindbladian evolution with non-Abelian symmetries: Ballistic front propagation in the SU(2) Hubbard model with a localized loss. Physical Review B 105 (19), 2022 mehr…BibTeX
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Máté, Mihály; Petrov, Klára; Szalay, Szilárd; Legeza, Örs: Compressing multireference character of wave functions via fermionic mode optimization. Journal of Mathematical Chemistry 61 (2), 2022, 362-375 mehr…BibTeX
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Tichai, A.; Knecht, S.; Kruppa, A. T.; Legeza, Ö.; Moca, C. P.; Schwenk, A.; Werner, M. A.; Zarand, G.: Combining the in-medium similarity renormalization group with the density matrix renormalization group: Shell structure and information entropy. , 2022 mehr…BibTeX
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Werner, Miklós Antal; Moca, Cătălin Paşcu; Kormos, Márton; Legeza, Örs; Dóra, Balázs; Zaránd, Gergely: Spectroscopic evidence for engineered hadron formation in repulsive fermionic $\textrm{SU}(N)$ Hubbard Models. , 2022 mehr…BibTeX
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2021
Babar, Rohit; Barcza, Gergely; Pershin, Anton; Park, Hyoju; Lindvall, Oscar Bulancea; Thiering, Gergő; Legeza, Örs; Warner, Jamie H.; Abrikosov, Igor A.; Gali, Adam; Ivády, Viktor: Quantum sensor in a single layer van der Waals material. , 2021 mehr…BibTeX
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Babar, Rohit; Barcza, Gergely; Pershin, Anton; Park, Hyoju; Lindvall, Oscar Bulancea; Thiering, Gergő; Legeza, Örs; Warner, Jamie H.; Abrikosov, Igor A.; Gali, Adam; Ivády, Viktor: Quantum sensor in a single layer van der Waals material. , 2021 mehr…BibTeX
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Barcza, Gergely; Werner, Miklós Antal; Zaránd, Gergely; Legeza, Örs; Szilvási, Tibor: Towards large-scale restricted active space calculations inspired by the Schmidt decomposition. , 2021 mehr…BibTeX
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Friesecke, Gero; Graswald, Benedikt R.; Legeza, Örs: Exact matrix product state representation and convergence of a fully correlated electronic wavefunction in the infinite basis limit. , 2021 mehr…BibTeX
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Gebhard, Florian; Legeza, Örs: Tracing the Mott-Hubbard transition in one-dimensional Hubbard models without Umklapp scattering. Physical Review B 104 (24), 2021 mehr…BibTeX
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Gebhard, Florian; Legeza, Örs: Tracing the Mott-Hubbard transition in one-dimensional Hubbard models without Umklapp scattering. arXiv, 2021 mehr…BibTeX
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Kovács, J.; Kruppa, A. T.; Salamon, P.; Legeza, Ö.; Zaránd, G.: Entanglement and seniority. , 2021 mehr…BibTeX
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Kovács, J.; Kruppa, A. T.; Salamon, P.; Legeza, Ö.; Zaránd, G.: Entanglement and seniority. , 2021 mehr…BibTeX
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Leszczyk, Aleksandra; Máté, Mihály; Legeza, Örs; Boguslawski, Katharina: Assessing the Accuracy of Tailored Coupled Cluster Methods Corrected by Electronic Wave Functions of Polynomial Cost. Journal of Chemical Theory and Computation 18 (1), 2021, 96-117 mehr…BibTeX
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Moca, Cătălin Paşcu; Werner, Miklós Antal; Legeza, Örs; Prosen, Tomaž; Kormos, Márton; Zaránd, Gergely: Simulating Lindbladian evolution with non-abelian symmetries: Ballistic front propagation in the SU(2) Hubbard model with a localized loss. arXiv, 2021 mehr…BibTeX
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